268 research outputs found
Delineation of fault zones using imaging radar
The assessment of earthquake hazards and mineral and oil potential of a given region requires a detailed knowledge of geological structure, including the configuration of faults. Delineation of faults is traditionally based on three types of data: (1) seismicity data, which shows the location and magnitude of earthquake activity; (2) field mapping, which in remote areas is typically incomplete and of insufficient accuracy; and (3) remote sensing, including LANDSAT images and high altitude photography. Recently, high resolution radar images of tectonically active regions have been obtained by SEASAT and Shuttle Imaging Radar (SIR-A and SIR-B) systems. These radar images are sensitive to terrain slope variations and emphasize the topographic signatures of fault zones. Techniques were developed for using the radar data in conjunction with the traditional types of data to delineate major faults in well-known test sites, and to extend interpretation techniques to remote areas
Use of polyethylene glycol coatings for optical fibre humidity sensing
Humidity induced change in the refractive index and thickness of the polyethylene glycol (PEG) coatings are in situ investigated for a range from 10 to 95%, using an optical waveguide spectroscopic technique. It is experimentally demonstrated that, upon humidity change, the optical and swelling characteristics of the PEG coatings can be employed to build a plastic fibre optic humidity sensor. The sensing mechanism is based on the humidity induced change in the refractive index of the PEG film, which is directly coated onto a polished segment of a plastic optical fibre with dip-coating method. It is observed that PEG, which is a highly hydrophilic material, shows no monotonic linear response to humidity but gives different characteristics for various ranges of humidity levels both in index of refraction and in thickness. It undergoes a physical phase change from a semi-crystal line structure to a gel one at around 80% relative humidity. At this phase change point, a drastic decrease occurs in the index of refraction as well as a drastic increase in the swelling of the PEG film. In addition, PEG coatings are hydrogenated in a vacuum chamber. It is observed that the hydrogen has a preventing effect on the humidity induced phase change in PEG coatings. Finally, the possibility of using PEG coatings in construction of a real plastic fibre optic humidity sensor is discussed. (C) 2008 The Optical Society of Japan
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Motivated monitoring by institutional investors and firm investment efficiency
We find that motivated monitoring by institutional investors mitigates firm investment inefficiency, estimated by Richardson's (2006) approach. This relation is robust when using the annual reconstitution of the Russell indexes as exogenous shocks to institutional ownership during the period 1995–2015 and after classifying institutional ownership by institution type. We also show that closer monitoring mitigates the problem of both over‐investing free cash flows and under‐investment due to managers’ career concerns. Finally, we document that the effectiveness of the monitoring by institutional investors appears to increase monotonically with respect to the firm's relative importance in their portfolios
Monitoraggio in area sismica di beni monumentali: tecniche NDT e procedure di verifica
Negli ultimi anni il concetto di vulnerabilità sismica è tristemente entrato a far parte delle
conoscenze anche dei non addetti ai lavori. Infatti, gli eventi sismici che hanno interessato dagli
inizi del ‘900 il territorio Italiano, hanno sistematicamente messo in risalto l’elevata vulnerabilità
sismica del nostro patrimonio edilizio, ivi compresi i beni monumentali, nonché, l’inesistenza di
qualsiasi attività di programmazione della manutenzione periodica ordinaria e straordinaria delle
strutture sismo-resistenti, che garantiscono nel tempo la conservazione delle loro capacità di
risposta alle perturbazioni esterne.Il progetto PON sul Monitoraggio in Area Sismica di SIstemi MOnumentali nasce con la
prerogativa di produrre uno strumento dedicato alla tutela di strutture a valenza storico – artistica,
attraverso un percorso di catalogazione, di analisi del bene inteso come elemento costituito da
elementi resistenti e da materiali, di studio del sito dove la struttura è ubicata e di attività di
monitoraggio
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Futures trading, spot price volatility and market efficiency: evidence from European real estate securities futures
In 2007 futures contracts were introduced based upon the listed real estate market in Europe. Following their launch they have received increasing attention from property investors, however, few studies have considered the impact their introduction has had. This study considers two key elements. Firstly, a traditional Generalized Autoregressive Conditional Heteroskedasticity (GARCH) model, the approach of Bessembinder & Seguin (1992) and the Gray’s (1996) Markov-switching-GARCH model are used to examine the impact of futures trading on the European real estate securities market. The results show that futures trading did not destabilize the underlying listed market. Importantly, the results also reveal that the introduction of a futures market has improved the speed and quality of information flowing to the spot market. Secondly, we assess the hedging effectiveness of the contracts using two alternative strategies (naïve and Ordinary Least Squares models). The empirical results also show that the contracts are effective hedging instruments, leading to a reduction in risk of 64 %
Multidisciplinary Management of Mastocytosis : Nordic Expert Group Consensus
Mastocytosis is a heterogeneous group of diseases defined by an increased number and accumulation of mast cells, and often also by signs and symptoms of mast cell activation. Disease subtypes range from indolent to rare aggressive forms. Mastocytosis affects people of all ages and has been considered rare; however, it is probably underdiagnosed with potential severe implications. Diagnosis can be challenging and symptoms may be complex and involve multiple organ-systems. In general it is advised that patients should be referred to centres with experience in the disease offering an individualized, multidisciplinary approach. We present here consensus recommendations from a Nordic expert group for the diagnosis and general management of patients with mastocytosis.Peer reviewe
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